Film guiding device



Aug. zo, 1935. E. w. KELLOGG' 2,012,130

FILM GUIDING DEVICE Filed Dec. 18, 1930 Fig. 1.

Edward WKeZZogg,

mmggwmlg H 5 ATTORNEY.

Patented Aug. 20, 1935 FILM GUIDING DEVICE Edward Washburn Kellogg,

Mooreatown, N.y J.

assigner, by mesne assignments, to Radio Cor: poration of America, New York. N. Y., a corpo.

ration of Delaware Application December 18, 1930, Serial No. 503,151

8 Claims.

My invention relates to sound recording and reproducing apparatus, and, more particularly, to sound recording and reproducing apparatus employing sound records of the flhn type.

In reproducing sound from records of this type, light from a suitable s ource is caused to pass through the sound track on the fllm and onto a photoelectric cell which transforms the light fluctuations into electrical pulsations, these pulsations being amplified and subsequently reproduced, as by means of' a loud speaker. 'I'he film is advanced through the reproducing machine at a constant rateand is so located that, in its travel, the sound track passes in the line of a narrow slit through which the light passes prior lto reaching the sound track. It is, accordingly,

necessary to insure that the sound track will always be in alignment with the slit, since failure to do so will result in improper reproduction. To this end, there have been proposed various film guiding devices.

The most common method of guiding fllms through sound reproducing machines has been to place the film over a flanged roller, usually located in close proximity to the light slit, with that edge of the film bearing the sound track in contact with the flange on the roller, the flange being so located with-respect to the slit that when one of the 'edges of the fllm'bears against the flange, the sound track will be properly aligned with the light slit. By reason of the fact that the fllm is subject to shrinkage and the width of the film handled varies, it is necessary, if close guiding is required, to bias the film toward the guiding flange. This has been accomplished, for example, by providing a movable flange on the end of the roller opposite to that oi' the fixed guide flange, and urging the movable flange against the free edge of the fllm, as by means of a spring acting on the movable flange, so that the sound edge of the fllm will be in constant engagement with the guide flange of the roller.

An arrangement of this sort has various disadvantages. For example, should the edge of the fllm tear longitudinally, as at the sprocket holes, the sprung or biasing flange will have no effect on the film unless it can move in towardr` the guiding flange a sufficient distance to accommodate itself to the reduced width of the film at the torn portion thereof. Also, by virtue of the lateral force exerted on the film at its edge by the biasing flange, there is a constant tendency for the film to buckle, and hence the action of the flange is not uniform and smooth. Another disadvantage resides in the comparative difficulty of' threading due to the fact that the biasing flange is encountered in the threading operation. This and other similar disadvantages are eliminated in my improved guiding deviceI it being the pri mary object of guiding mechanism objections noted. Another object of my i fllm guiding mechanism in its action and which w itself to any fllm regardl A further object of my invention 'to provide a film which will befree from the nvention is to provide a which will be positive ill readily accommodate ess of its width.

my invention is to provide a film guiding mechanism which will constantly urge the lm toward a suitable guide. will eliminate buckling, form in its action.

Still another object of my invention is to provide a film guiding mechanism in which the biasing tendencyimay be regulated at will.

It is another object of my invention to a fllm guiding mechanism wherein the exerted upon the film Still another object of provide pressure may be regulated at will.

my invention is to provide a film guiding mechanism which will permit quick and easy threading oi' the lm.

A further object of my invention is to provide a film guiding mechanism which is of compact. but durable construction, eillcient in use, and

particularly well suited to nomical manufacture.

the requirements of ecoand will be smooth and uni- 1g 00 The novel features that I consider characters istic of my invention are larity in the appended set forth with particuclaims. the invention itself, however, both as to its organization and its' method of operation, together with additional 0biects and advantages thereof being best understood from the following embodiment when taken description of a specific in connection with the accompanying drawing in which Fig. 1 is a diagrammatic view of a. reproducing system illustrating the application of my improved fllm guiding mechanism thereto,

Fig. 2 is a perspective applied to a guide roller,

view of my invention al Fig. l3 is a top plan view thereof, and Fig. 4 is a sectional view taken on the line IV-IV 0f F18'. 3 in the direction of the arrows.

Referring to the drawing, the system shown in Fig. l comprises a take-off reel i0 from which a film! I is fed, by means of a plurality of sprockets I2, Il, I! and i8,

through a picture gate I1, around a guide pulley I0,

and through a sound gate Il, the film being then wound up on a takeup reel 20. The film II 4ture gate l1 in a step-by is fed through the pic- -step manner by means (not shown) well known to those skilled in the art, while its movement through the sound gate I9 is continuous and uniform. Light from a source 2l passes through an optical system, illustrated at 22, which condenses the light, in the form of a relatively narrow beam, onto a sound track 23 of the film Il, the light being sharply defined on the sound track 23 by means of a slit 24, and thence passing on to a light sensitive element, such as a photoelectric cell 25, the output of which is connected to any suitable amplifier.

The guide pulley or roller I8, around which the film Il has a substantial wrap, is mounted for rotation on a shaft fixed to a suitable base member or support 3|, such as the frame of the machine or a partition therein, it being noted that the shaft 38 is perpendicular to the support 3|. In order to maintain the-sound track 23 of the film I I in constant and proper alignment 'withl the slit 24, 1 provide the roller I8, at one rend thereof, with a xedguide flange 32 against which the sound edge 33 of the iilm I I is adapted to. bear as it is fed through the machine. The

roller I8 may, if desired, also be provided with 4a second ilange on the other end thereof, but I prefer to omit the latter flange as this will facil- .--itate threading of the film.

u Fixed to the support 3i is an angular bracket 34' for supporting a biasing roller 35 which maintains the film in contact with the 'roller I8 and insures constant contact of the sound edge 33 with the flange 32 in a manner hereinafter to be described. .The roller 35, which may take the place of the usual pressure roller, may, if desired, be made of a hardl material, or it may be covered witha soft, resilient material, such as rubber. A block 36, provided with a lug portion 31, is mounted on the bracket 34 for rotation, on a setscrew 38, about an axis parallel to the plane of the support 3l and lying in a plane at right angles to the axis 30 of the roller I8, the block 36 being Yfixed in any desired position relative to the roller I8 b'y means of the setscrew 38. The free end of the block 36 is provided with a bore for receiving a shaft or pin 39, the ends of which extend out beyond the block 36. J ournalled on the ends of the pin 39 is a yoke 40, the upper end of which is provided with bearings 4I for the reception of a shaft 42 which carries the biasing roller l35. It will thus be seen that the .yoke 40 may be swung on the pinl 39 for movement toward and away from the roller I8, so that the roller may be brought into contact with the roller I8 or removed from contact therewith, as may be desired The pin 39 acts, of course; as a fixed axis about which the roller 35 is swung, and

ythe shaft or axis 42 of the roller 35 always remains parallel to the pin 39, no matter what its position may be. At the same time, the roller -35 is adjustable about the set screw 38 in a manner to permit location thereof with its axis or shaft 42 disposed at an angle to the axis or shaft 30 of the guide roller- I8 but with neither of said axes lying in a common plane, whereby the roller 35 is adapted, upon engaging the film II, to impart a force thereto urging the lm -longitudinally of the roller and, as illustrated in Fig. 2, toward the flange 32.

Inorder to insure the roller 35 being in contact with the guide roller I8 during the operation of the machine, I insert a coil spring 45 between the yoke and an adjusting screw 4B, threaded in the lug 31 of the block 36. One end of the spring isltted within a recess 41 in the yoke completed, the spring 40, while the other endthereof is received within the hollow end portion 48 of the adjusting screw 46. To adjust the tension of the spring 45, and hence the pressure of the roller 35 of the film Il and roller I8, it is merely necessary to turn the adjusting screw 46 in the threads of the lug 31. A spring latch 50 is provided on the yoke 40 for engagement with a linger 5I on the lug 31 to retain the rollers I8 and 35 out of contact with each other against the action of the spring 45. Hence, when it is desired to thread the film, the roll-er 35 may be removed from contact with the roller I8 by pushing backward on the yoke di), swinging the latter about the pin 39 until the latch 50 catches and engages with the finger 5I. When the threading operation has been the finger 5I and the roller 35 will be automatically forced into Contact with the film Il and the roller I8 under the action of the coil spring The block 36 is initially adjusted about the screw 38 so that it will be angularly related to the roller I8. Consequently, the yoke 40 and, hence, the shaft 42 angularly related to the roller I8. In other words, when the block 36 is adjusted to and locked in the position shown in Fig. 2, instead of being perpendicular to the support 3l as is the shaft 30 of the roller I8, the shaft 42 of the roller 35 is at an angle to the support 3l and, therefore, also at an angle to the shaft 30 of the roller I8. The angle between the shafts 38 and 42 may be of any desired degree to suit particular requirements, although, fo-r example, an angle ofbetween 2 and 5 would ordinarily be suflicient. As the rollers I8 and 35 and the film II travel in the direction of the arrows A, B, and C, respectively;Q the component of the force applied by the roller 35 on the film II acting toward the flange 32 will force the lrn toward that flange, and thus the edge 33 of the lrn will be in constant contact therewith. When it is desired to change the biasing tendency of the roller 35, it is merely necessary to loosen the adjusting screw 38 and turn the block 36 and the roller 35 to any desired angle with respect to the roller 38. This will, of course, correspondingly change the biasing component of the force applied by the roller 35onthe filmIl.

It will also be obvious that, inasmuch as the roller 35 acts upon the surface of the film II, variations inthe width of the film will not affect its operation. Furthermore, because the roller 35 acts on the surface of the film, it will avoid buckling of the film suchv as would be caused by a force applied to the edge thereof, and will also avoid the objectionable scraping of the edge of the film which often occurs Where the film leaves a roller provided with flanges, one of which is pressed against the lm by means of a spring. It will thus be seen that I have provided a lm guiding mechanism that is smooth and uniform in its action, variable at will to change its biasing action, ling, and, at the same ing of the film.

Although I have shown and described a certain specic embodiment of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as isnecessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

time, permits easy threadof the roller 35 will also be which eliminates and prevents buck.

latch 58 is released from l 'Llncombinatiomaiilmguiderollenaiiim biasing roller adapted to engage said guide roller, said rollers having their axes angularly disposed with respect to each other but neither of said axes in a common plane, whereby said biasingrollerisadaptedtoapplytoaiilmpassing between it and said guide roller a force urging said i'ilm longitudinally ot said guide miler, and means constantly urging one oi' said rollers toward the other.

2. In combination, a nlm guide roller, a tlim biasing roller adapted to .engage said guide roller, said rollers having their axes angularly disposed with respect to each other but neither ot said axes lying in a common plane, whereby said biasing roller is adapted to apply to a iilm passing between it and being so disposed that the film is biased toward said flange, and means for varying the angle between the axes o! said rollers.

4. In combination, a guide roller, a flange on said guide roller, a second roller mounted for yielding engagement with said guide roller whereby a iilm is receivable between said rollers 'and 18 adapted t0 be Dressed against said guide roller. said second roller having lts axis at an angie to the axis oi' said guide roller and being so disposed that the iilm is biased toward said ange, means for varying the angle between the axes o! said rollers, and means for adjusting the pressure between said rollers.

5. In combination, a guide roller. a iiange on said guide roller, a support, a yoke hinged to axis at an angle to.

said support for movement toward and away from said guide roller, a biasing roller mounted on said yoke and contacting with said guide roller for imparting a biasing force toward said iiange, means for varying the angle between said rollers. and means for varying the pressure between said rollers.

6. In combination, a base member, a nim guide roller mounted on said base member, a support on said base member, a mm biasing roller mounted on said support tor pivotal movement about an axis in a plane at right angles to the axis of said guide roller, whereby the angle between the axes of said rollers may be changed at will, means for releasably retaining said nlm biasing roller in set position, and spring means urging said iilm biasing roller toward said film guide roller in a manner such that the axis of said lm biasing roller always remains parallel to a fixed axis.

7. The invention set i'orth in claim 6 characterized in that said support includes a yoke' member pivotally mounted for movement toward and away from said iilm guide miler, said iilm biasing roller being mounted on said yoke for rotation about an axis parallel to the pivotal axis of said yoke, and characterized in that said iixed axis is constituted by said pivotal axis.

8. In combination. a base member, a film guide roller mounted on said base member, a support on said base member. a yoke mounted on said support for movement about one axis toward and away from said guide roller and about a second axis at right angles to said first named axis, a spring constantly urging said yoke toward said guide roller, a nlm biasing roller rotatably mounted on said yoke, said biasing roller being maintained in engagement with said guide roller under the influence of said spring and said yoke being movable about said second named axis whereby to change the angle between the axes oi' said guide roller and saidblasing roller, and means for releasably retaining said yoke in set position.

EDWARD WASHBURN KELLOGG. 

